(1) Field of the Invention
The present invention relates to a towed, acoustic noise generating source.
(2) Description of the Prior Art
It is well known in the towed acoustic noise source art that there are a number of off-the-shelf, towable, underwater acoustic noisemakers that provide an easy and inexpensive way to generate in-water noise signals having reasonable bandwidth and source level characteristics. For example, one such well-known device is an underwater siren that includes a multi-bladed rotor with a plurality of holes in each rotor blade. These holes generate sound as the blades are turned by the water flow. Such devices however typically have the disadvantage that the generated noise waveform characteristics are not very controllable. These devices also have the drawback that the specific waveforms that they generate cannot be easily changed. What is needed is a way to overcome the present inherent lack of control over the generated sound waveforms that are produced by the prior art devices while at the same time keeping the noise-generating source simple and lightweight.